RFID tags are used to store information which can be wirelessly accessed with an RFID reader. For example electronic product codes (EPCs), keys, or passwords may be stored on an RFID tag. Such information may be written into the memory of an RFID tag during an initialisation process, either at assembly of the tag, or when the tag is to be used.
The initialisation process may be performed using an RFID reader (or RFID interrogator). The reader requests the tag to store a block of data, such as an EPC, on a memory in the RFID tag. The request may specify a location in the memory at which to store the data block. The tag receives this request and stores the requested data block at the requested memory location. This process may be repeated on multiple RFID tags.
Errors can develop in the stored data. Error correction techniques allow recovery of the original data when errors develop. Error correction codes (ECC) add redundant data (known as error correction data or parity) to the data block. The redundant data can be used to check data in the data block and restore original data if errors develop.